diff --git a/modules/users/s6-rc.nix b/modules/users/s6-rc.nix
index f750d58da..02b2797fa 100644
--- a/modules/users/s6-rc.nix
+++ b/modules/users/s6-rc.nix
@@ -236,7 +236,7 @@ in
 
       fs.".profile".symlink.text = ''
         function startS6() {
-          local S6_TARGET="''${1:-default}"
+          local S6_TARGET="''${1-default}"
 
           local S6_RUN_DIR="$XDG_RUNTIME_DIR/s6"
           local COMPILED="$S6_RUN_DIR/compiled"